Shoe having a cushioned insole



Dec. 10, 1968 A. A. MATTOS 3,414,988

SHOE HAVING A CUSHIONED INSOLE Filed Dec. 7, 1965 2 Sheets-Sheet 1 dz 2% flINVENTZOER fl 0y Ma 0,5

ATTORNEYS Dec. 10, 1968 A. A, MATTOS SHOE HAVING A CUSHIONED INSOLE 2 Sheets-Sheet 2 Filed Dec. 7, 1965 FIG.4

FIG.5

AITORN EYS United States Patent 3,414,988 SHOE HAVING A 'CUSHIONED INSOLE Anthony A. Mattos, Bristol, R.I., assignor to Marbill firmgany, Providence, RJ., a corporation of Rhode s an Filed Dec. 7, 1965, Ser. No. 512,097 4 Claims. (Cl. 36-2.5)

ABSTRACT OF THE DISCLOSURE A shoe whose insole comprises a relatively thick, resilient cushioning layer of porous plastic foam and at selected areas a relatively thin, substantially non-resilient, shock-damping ply of unicellular plastic foam.

This invention pertains to footwear, more especially to a shoe whose bottom structure, while providing a soft surface for contact with the wearers foot, also comprises means for absorbing the shock of sharp impact of the shoe with the ground or floor, for example as when the shoe is worn while playing basketball-a game which demands sudden push-offs in starting; instantaneous stopping, and wherein the player may leap into the air and drop with heavy impact of his feet on the floor.

Shoes worn while playing basketball, for example, customarily have thick outer soles of resilient material, such as vulcanized rubber or synthetic plastic, but such outer soles do not yield instantaneously, in response to sudden impact, to an extent sufficient to avoid the transmission of shock to the wearers foot. In the attempt to protect the wearers foot from damage, it has heretofore been proposed to provide the shoe with an insole comprising a thick layer of highly porous sponge, for example, sponge rubber or plastic, as a cushion for the foot, but basketball player have complained that such a deep and very soft cushion permits the foot to rock or otherwise move relatively to the outer sole, especially when the player stops short or tries to start quickly, giving to the player a feeling of insecurity as though, for example, the shoe were much too large. Further, a deep, soft, coarsely porous layer of ordinary sponge is found to break down quickly or to wear through, even during a single game, and in the opinion of professional players, a deep layer of ordinary porous sponge, even when new, does not prevent the transmission of the shock of impact to the wearers foot.

The principal object of the present invention is to provide a shoe, in particular a basketball shoe, affording firm support although having asufficiently soft surface to provide comfort to the sole of the wearers foot, while, at the same time, embodying means operative effectively to prevent the transmission of the shock of sudden impact to the foot.

Other and further objects and advantages of the invention will be pointed out in the following more detailed description and by reference to the accompanying drawings wherein:

FIG. 1 is a plan view of an embryo insole in accordance with the present invention and useful in the attainment of the above objects;

FIG. 2 is a bottom view of the embryo insole of FIG. 1;

FIG. 3 is a section, to larger scale, on the line 33 of FIG. 1;

FIG. 4 is a side elevation of a shoe embodying the present invention;

FIG. 5 is a fragmentary section on the line 55 of FIG. 4;

FIG. 6 is a fragmentary section, to larger scale than FIG. 5, diagrammatically illustrative of the internal structure of the cushioning ply;

3,414,988 Patented Dec. 10, 1968 FIG. 7 is a view, similar to FIG. 6, but illustrates by contrast, the internal structure of the shock-deadening ply;

FIG. 8 is a diagrammatic bottom view of a last, provided with a cavity in its bottom, and useful in the practice of the present invention; and

FIG. 9 is a fragmentary section on line 99 of FIG. 8.

Referring to the drawings, the numeral 10 indicates a shoe of that general type in which the present invention finds utility-this shoe having the upper 11usually of textile material; the outer sole 12, which may, for example, be of vulcanized rubber or a resilient synthetic plastic; the foxing 13, here shown as integral with and of the same material as the outer sole and which, as usual, extends upwardly along the lower margin of the upper to which it is bonded; and the inner sole 14 which, as shown in FIG. 5, rests directly upon the upper surface of the outer sole.

Referring to FIGS. 3, 6 and 7, this novel inner sole comprises a textile ply 15 constituting the uppermost or lining element of the inner sole, this textile ply being bonded to an underlying cushioning ply 16 of sponge rubber or the like which has been blown, under controlled conditions, to form a soft, coarse-meshed foam as indicated in FIG. 6.

Bonded to the underside of this relatively soft foam ply there is a substantially impervious ply 17 of so-called rag stock such as is customarily employed in the manufacture of rubber and similar shoes and consisting of fibrous material embedded in an elastomeric bonding material such, for example, as rubber, and which here provides an impervious stiffening ply for the insole and whose undersurface is bonded to a ply 18 of textile fabric.

A relatively thin, inert, shock-damping ply 19 is bonded to the underside of the textile ply 128, this shock-damping ply 19 being, for example, of a composition such as is disclosed in the patent to Catalfano et al., No. 3,054,126, Sept. 18, 1962, or some similar material, which has been blown under such confinement that: it was unable to expand to more than a fraction of the volume which it would have if blown without confinement, and wherein gasfilled cells, resultant from the action of the blowing reagent, do not communicate with each other to any substantial extent, forming what is commonly known as a unicellular structure, wherein each of the tiny individual cells is filled with gas under pressure. This ply 19 has little resiliency but is characterized by the fact that it resists the transmission of sudden shock vibrations and thus the foot of the wearer is protected from injury by the shock of contact of the outer sole with the floor. A ply 20- textile material is bonded to the underside of the shock-deadening ply 19.

As illustrated in FIG. 2, the shock-damping ply 19 with the attached textile ply 20 are so contoured that this composite ply is confined substantially to those areas of the shoe bottom at which the maximum degree of shock ordinarily occurs, that is to say, at the ball portion B, the

arch or inner portion of the shank, as shown at S, and at the heel H.

In the preparation of the insole according to the preferred procedure there may first be provided textile piece goods, for example a woven cotton drill such as is customarily employed in the lining of footwear, and to one side of any desired length of this material there is applied a coating of a sponge composition comprising a blowing agent of customary type. The coated piece material is then introduced into conventional apparatus and heated sufficiently, while under predetermined pressure, to expand the compound to a desired thickness thereby providing the textile material with a uniformly thick layer of sponge on one side.

The foamable compound used in preparing the ply 16 is desirably such that it will expand in volume approximately 100% if foamed when unconfined, making a very soft and coarse-grained foam structure in which the major portion of the cells intercommunicate. In accordance with the present invention the blowing of the material forming the cushioning ply 16 is so restricted during heat-treatment of the coated textile fabric in the piece, as above described, that, in a unit volume of the cured material the included air or gas constitutes approximately 50% of the volume. In accordance with the preferred procedure the resultant sponge layer 16 may be within a range of of an inch to /2 inch, but a thickness of approximately A; inch appears to give optimum results.

Having prepared the yard-goods with its adherent layer of sponge, as just described, pieces, each of proper size and shape to form the duplex upper ply 15, 16 of an insole, may be cut by means of a die.

To one side of a sheet of selected rag stock or similar material there is bonded a layer of textile fabric which, for example, may be of a coarse plain weave and which constitutes the bottom layer 18 of the insole, except for those areas at which the shock-deadening material is to be located, and from this two-ply material pieces are die-cut, each appropriate to constitute the stiffening ply for the desired inner sole.

The shock-deadening material is desirably prepared by coating one side of a selected length of textile yard-goods (for example, cotton of a plain weave but of a firmer texture than that secured to the lower side of the rag stock ply), with the patented compound above referred to or some similar material, applying sufiicient compound to produce a finished foam ply of A inch thickness, for example, or some equivalent material, and after coating this textile fabric (thus forming a two-layer ply), and before blowing the compound, there may be die-cut therefrom pieces, each of the desired shape and size to insure the shock-damping action at the ball portion, shank portion and heel portion of the insole of a completed shoe. A duplex ply such as just described, comprising the layers 19 and 20, is now combined with the other layers or plies as by adhesively bonding the layer 19 to the textile ply 18, thus forming a multi-ply embryo insole.

In completing the shoe, having provided the embryo insole as above described and having assembled the shoe upper with a suitably molded outer sole 12, provided with the integral foxing 13; and having bonded the marginal portion of the upper to the outer sole and foxing, the embryo insole, as above described, is placed within the upper with its ply 20 and parts of the ply 18 in contact with the upper surface of the outer sole. A last is now introduced, a vulcanizing last being employed whose bottom is conventional (except that if it be desired to provide the shoe with an arch support; the last bottom is hollowed out at the inside of the arch to form a cavity, as shown at K, FIG. 9). Pressure is now applied to the outer sole as by means of a customary outsole press so that the layer 19 is confined above and below, respectively, by the impervious rag stock ply 17 and by the last bottom, and the assemblage is subjected to customary vulcanizing treatment. Since the foam-forming compound is confined, as just described, it can expand no more than approximately 33% (except at the location of the cavity K, if such cavity be provided in the last bottom). The foam thus produced is unicellular and desirably of the order of inch in thickness, except at the location of the cavity K. The cells in this foam are very small, predominantly independent, and are filled with gas under substantial pressure. This ply 19 is relatively thin as compared with the cushioning ply 16; it is denser than the cushioning ply; and is substantial- VII 1y inert as respects the transmission of vibration and does not yield appreciably to downward pressure. Thus, it is highly effective in damping the transmission of shock waves upwardly to the sole of the wearers foot.

At that portion of the ply 19 which underlies the cavity K in the last bottom the gas pressure evolved, in the blowing of the ply 19, is able to lift the material immediately above it and form a permanent elevation, in shape complementary to the shape of the cavity K, thus providing the shoe with an arch support.

While the invention has herein been described with particular reference to its utility in a basketball shoe, it is contemplated that it may be found useful in other types of footwear where protection of the mans foot from impact shock is desirable.

I claim:

1. In combination, in a shoe having an upper and an outer sole, an insole bonded to the outer sole and which includes an upper, foot-contacting, cushioning ply of textile material, the undersurface of said ply being bonded to a resilient ply of foam comprising a cellular structure wherein a substantial percentage of the cells communicate with each other, said last-named ply being of the order of A of an inch in thickness, and a lower ply of shockdeadening material comprising unicellular foam wherein the gas entrapped within its cells is under compression, wherein a ply of rag stock underlies the cushioning foam ply to impart stiffness to the insole, and the ply of unicellular foam is bonded to an underlying ply of textile material.

2. In combination, in a basketball shoe having an upper and an outer sole, an inner sole comprising an upper, lining ply of textile fabric bonded to a cushioning ply of foam many of whose cells intercommunicate and which is of a thickness approximately /s of an inch, a layer of stiffening material underlying and bonded to said cushioning ply, a textile ply bonded to the underside of the stiffening ply, a ply of shock-deadening material bonded to the underside of said last-named textile ply and consisting of unicellular foam of the order of of an inch in thickness and wherein the gas entrapped in the foam cells is under pressure, and a ply of textile fabric bonded to the undersurface of said shock-damping ply, the shock-damping ply and its underlying textile fabric being confined to those areas of the inner sole at which maximum shock occurs during use.

3. A shoe according to claim 2, further characterized in that the insole has a multi-ply elevation at the inside of the arch constituting an arch support, one of the constituent plies of said elevation being of unicellular plastic foam.

4. A shoe according to claim 2, further characterized in that in the shock-deadening ply voids constitute approx imately one-third of the unit volume.

References Cited UNITED STATES PATENTS 3,170,250 2/1965 Scholl 3644 3,257,742 6/1966 Feinberg 3644 2,798,312 7/1957 Muller 362.5 2,878,523 3/1959 Hardy 264244 3,085,294 4/1963 Rosenba-um 264-244 3,146,536 9/1964 Crowley 36-32 PATRICK D. LAWSON, Primary Examiner.

US. Cl. X.R. 3644 

